photo: Skyline Solar

This post first appeared on Grist.

Grist’s David Roberts sent out a Tweet to his Tweeps today asking which city has installed the most solar. I’ve got an answer for you, David: Nipton, California.

The desert micropolis – population 38 – announced Thursday that it had installed a solar array that will provide 85 percent of its electricity. (The population of the outpost on the edge of Mojave National Preserve spikes to 250 or so during tourist season.)

The solar system is ground-mounted rather than on rooftops and only generates 82 kilowatts. But what is notable is the technology developed by Skyline Solar, a Silicon Valley startup I first wrote about for Grist last year.

The company’s power plants resemble solar thermal parabolic trough installation that deploy long rows of mirrors to heat tubes of liquid suspended over the arrays to create steam that drives an electricity-generating turbine.

Skyline’s system is purely solid state, however. Each 120-foot-long trough concentrates the sun on photovoltaic modules attached to the edges of the arrays. That boosts the solar cell’s electricity production as does a tracking mechanism that allows the arrays to follow the sun throughout the day.

Such concentrating photovoltaic systems – which Skyline calls “high gain solar “ – have been a niche market due to their relatively high costs. But as solar cell prices decline and solar thermal projects get bogged down in environmental disputes, they have become increasingly attractive as they can be built near utility substations and plugged directly into the grid without the need to build expensive new transmission systems.

Skyline has pushed to lower costs by using common materials – glass, steel – and designing the arrays so their components can be mass-produced by automotive manufacturers. The company last year struck a deal with the Michigan subsidiary of Canadian auto manufacturing giant Magna International to make components for its HGS 1000 solar system.

In other news on the solar frontier Thursday, Silicon Valley startup MiaSolé said the National Renewable Energy Laboratory had confirmed that the company’s copper indium gallium selenide solar cells have 13.8 percent efficiency in production. Such thin-film cells typically have a lower efficiency than standard polysilicon solar cells but are cheaper to manufacture. But with an efficiency approaching 14 percent, MiaSolé could give some standard module makes a run for their money.

Photo: Amonix

In The New York Times on Wednesday, I wrote about Southern California solar company Amonix scoring one of the biggest rounds of green tech funding this year — $129.4 million from investors led by Silicon Valley heavyweight Kleiner Perkins Caufield & Byers:

In one of the biggest green technology deals of the year, a prominent Silicon Valley venture capital firm is leading a $129.4 million investment in a long-promising solar technology that is starting to gain traction in the United States.

The venture firm, Kleiner Perkins Caufield & Byers, and other investors are making a big bet on Amonix, a company in southern California that has spent 20 years developing concentrating photovoltaic power systems that resemble gigantic solar panels.

Plastic lenses focus the sun on tiny but highly efficient solar cells to generate more electricity than conventional photovoltaic panels. The so-called multijunction cells, which were first developed to power satellites, use fewer expensive semiconducting materials like silicon.

“We have reviewed hundreds of solar companies, and Amonix stands out to us as one that has breakout potential,” said Ben Kortlang, a partner at Kleiner Perkins who formerly helped lead the alternative-energy investing unit at Goldman Sachs. “We believe this is the low-cost solar technology for sunny climates.”

Photo: SolFocus

In The New York Times on Thursday, I wrote that Silicon Valley startup SolFocus is building the first large concentrating photovoltaic power plant in the United States:

The nation’s first big concentrating photovoltaic power plant is under construction in the California desert.

SolFocus, a Silicon Valley startup, is building the one-megawatt solar farm for Victor Valley College in Victorville, a desert community northeast of Los Angeles.

The company builds large solar panels that contain small mirrors that concentrate sunlight onto tiny, high-efficiency solar cells. Though more expensive than conventional solar cells, they use a fraction of the silicon and produce more electricity. That means less land is needed for a SolFocus power plant than one deploying conventional photovoltaic panels.

The SolFocus panels are mounted on trackers that follow the sun throughout the day. While SolFocus has built power plants in Europe, the California project is its first solar farm in the United States. Victor Valley College selected SolFocus after receiving competitive bids from several companies that install conventional photovoltaic panels and thin-film solar systems.

“After reviewing several options for a solar provider, SolFocus demonstrated that it could deliver the best value in solar energy for the college,” Robert Silverman, Victor Valley College’s president, said in a statement. The SolFocus power plant will supply about 30 percent of the college’s overall electricity demand.

SolFocus’ technology needs strong, direct sunlight to maximize electricity production. “If this deployment had been in somewhere in Northern California or Washington or Oregon, we probably wouldn’t have won the battle,” said Nancy Hartsoch, a vice president of marketing at SolFocus. Ms. Hartsoch added that in desert regions, the company’s technology generates electricity at prices competitive with traditional photovoltaic panels.

photo: SolFocus

Silicon Valley solar power company SolFocus on Monday said it has signed a deal to install 10 megawatts of concentrating photovoltaic panels in Greece and expects to build its first project in the United States later this year.

SolFocus’ solar panels use small curved mirrors to focus sunlight on a high-efficiency solar cell to maximize production of electricity while reducing the use of expensive silicon. SolFocus claims its panels are up to twice as efficient as conventional photovoltaics. But given the relatively high costs of such systems, the company decamped for Europe where governments in Spain and Greece pay a premium rate for solar energy through “feed-in tariffs.”

But the recently enacted federal economic stimulus package, which includes billions of dollars dedicated to renewable energy projects, is luring SolFocus home.

“Now with the new stimulus package we believe the big year for us in the U.S. will be 2010,” Nancy Hartsoch, SolFocus’ vice president of corporate marketing, told Green Wombat.

Meanwhile, utilities are ramping up installations of photovoltaic solar projects. California utility PG&E (PCG) two weeks ago, for instance, unveiled a program to install 500 megawatts of ground-mounted solar panels over the next five years. The projects would essentially be small-scale solar farms generating between one and 20 megawatts of electricity and built on utility-owned land near substations.

“That‘s the perfect spot for our technology,” says Hartsoch.

Not so perfect is PG&E’s Northern California territory. SolFocus’ power plants need direct sunlight to most efficiently produce electricity. But Hartsoch says the southern reaches of PG&E’s service area offer sufficient sunlight and as production costs fall it’ll become cost effective by 2012 to build concentrating photovoltaic power plants in Silicon Valley and elsewhere in Northern California.

She says SolFocus’ first solar farms will likely be built for municipal-owned utilities and the company currently is in discussions with cities in the Southwest.

The deal announced Monday with Greece’s Samaras Group expands a 1.6 megawatt agreement the companies signed last year.

About Green Wombat

Green Wombat is written by
Todd Woody, a veteran environmental journalist based in California who writes for The New York Times, the Los Angeles Times, Grist and Yale e360. He's one of the few people on the planet who have held a northern hairy-nosed wombat in the wild.

Todd formerly was a senior editor at Fortune magazine, an assistant managing editor at Business 2.0 magazine and the business editor of the San Jose Mercury News.